Public Cloud is the delivery paradigm for Cloud Computing services delivered over public networks from publicly available tenanted infrastructure. Although generally available, Public Cloud services are not inherently less secure than other Cloud offerings, often making use of technologies such as VPN, SSL and multi-factor authentication to ensure security and privacy of data.
Typically, Public Cloud service offerings provide generic (although often sophisticated) functionality that can be consumed by a large potential customer base sharing common requirements providing opportunity for customers to benefit greatly from economies of scale in the commercial models of service providers enabling the provision of services at very low price points.
Notable examples of Public Cloud services include Office 365, Salesforce, Amazon AWS and Adobe Creative Cloud.